Prognostic Value of Overexpressed p16INK4a in Vulvar Cancer: A Meta-Analysis

European Society of Gynaecological Oncology Guidelines for the Management of Patients with Vulvar Cancer - Update 2023

BACKGROUND

As part of its mission to improve the quality of care for women with gynecological cancers across Europe, the European Society of Gynaecological Oncology (ESGO) first published in 2017 evidence-based guidelines for the management of patients with vulvar cancer.

OBJECTIVE

To update the ESGO guidelines based on the new evidence addressing the management of vulvar cancer and to cover new topics in order to provide comprehensive guidelines on all relevant issues of diagnosis and treatment of vulvar cancer.

METHODS

The ESGO Council nominated an international development group comprised of practicing clinicians who provide care to vulvar cancer patients and have demonstrated leadership through their expertize in clinical care and research, national and international engagement and profile as well as dedication to the topics addressed to serve on the expert panel (18 experts across Europe). To ensure that the statements were evidence-based, new data identified from a systematic search were reviewed and critically appraised. In the absence of any clear scientific evidence, judgment was based on the professional experience and consensus of the international development group. Prior to publication, the guidelines were reviewed by 206 international practitioners in cancer care delivery and patient representatives.

RESULTS

The updated guidelines cover comprehensively diagnosis and referral, staging, pathology, pre-operative investigations, surgical management (local treatment, groin treatment, sentinel lymph node procedure, reconstructive surgery), (chemo)radiotherapy, systemic treatment, treatment of recurrent disease (vulvar, inguinal, pelvic, and distant recurrences), and follow-up. Management algorithms are also defined.

Precursors, pathways of carcinogenesis and molecular markers of vulvar squamous cell carcinoma. Literature review

The review analyzes and summarizes the results of the studies on the pathogenesis of  vulvar squamous cell carcinoma and its diagnostic features, reviews precursors and  molecular subtypes of carcinomas. Despite the relatively low incidence of this tumor, over the past few decades, there has been an upward trend in its incidence, including the incidence among young women. According to the latest World Health Organization classification of lower genital tumors from 2020, vulvar squamous cell carcinoma is divided into human papillomavirus (HPV) associated and HPV-independent. While these carcinomas are often morphologically similar, their mechanisms of carcinogenesis, precursors, and clinical outcomes are different. Just the detection of virus DNA in a tumor is not enough to establish HPV status. Meanwhile immunohistochemical detection of the expression of p16 and p53 proteins allows not only to separate two pathogenetic pathways of carcinogenesis, but also to identify its molecular subtypes. The data on the possible use of p16 and p53 expression as the disease prognosis molecular markers have been obtained. Currently, the tactics of treatment and monitoring patients does not depend on the HPV status of carcinoma; however, the results of recent studies suggest that women with HPV positive vulvar cancer have significantly higher survival rates and a lower risk of recurrence. Understanding the mechanisms of carcinogenesis and improving its diagnosis will advance the assessment of the individual risk of the progression of precancerous lesions, as well as the outcome and the occurrence of tumor recurrence. 

Prognostic value of high-risk human papillomavirus DNA and p16INK4a immunohistochemistry in patients with anal cancer: An individual patient data meta-analysis

BACKGROUND

High-risk human papillomavirus (hrHPV) types represent the aetiological agents in a major proportion of anal squamous cell carcinomas (ASCC). Several studies have suggested a prognostic relevance of HPV-related markers, particularly hrHPV DNA and p16^INK4a (p16) protein expression, in patients with ASCC. However, broader evaluation of these prognostic marker candidates has been hampered by small cohort sizes and heterogeneous survival data among the individual studies. We conducted an individual patient data (IPD) meta-analysis to determine the prognostic value of hrHPV DNA and p16 in patients with ASCC while controlling for major clinical and tumour covariates.

PATIENTS AND METHODS

A systematic literature search was conducted to identify all published studies analysing p16 alone or in combination with hrHPV DNA and reporting survival data in patients with ASCC. Clinical and tumour-related IPD were requested from authors of potentially eligible studies. Survival analyses were performed with a proportional hazard Cox model stratified by study and adjusted for relevant covariates. The study-specific hazard ratios (HRs) for the exposures were pooled using a random-effects model. Kaplan-Meier curves from different studies were pooled per exposure group and weighted by the study's total sample size.

RESULTS

Seven studies providing IPD from 693 patients with ASCC could be included in the meta-analysis. Seventy-six percent of patients were p16+/hrHPV DNA+, whereas 11% were negative for both markers. A discordant marker status was observed in 13% of cases. Patients with p16+/hrHPV DNA+ ASCC showed significantly superior overall survival (OS) compared with patients with p16-/hrHPV DNA- tumours (pooled adjusted HR = 0.26 [95% confidence interval {CI}, 0.14-0.50]) with pooled three-year OS rates of 86% (95% CI, 82-90%) versus 39% (95% CI, 24-54%). Patients with discordant p16 and hrHPV DNA status showed intermediate three-year OS rates (75% [95% CI, 56-86%] for p16+/hrHPV DNA- and 55% [95% CI, 35-71%] for p16-/hrHPV DNA+ ASCC).

CONCLUSION

This first IPD meta-analysis controlling for confounding variables shows that patients with p16+/hrHPV DNA+ ASCC have a significantly better survival than patients with p16-/hrHPV DNA- tumours.

P16 and HPV Genotype Significance in HPV-Associated Cervical Cancer-A Large Cohort of Two Tertiary Referral Centers

The expression of p16 is a good surrogate of human papillomavirus (HPV) infection in HPV-associated cancers. The significance of p16 expression, HPV genotype and genera in the outcome of patients with HPV-associated cervical cancer (CC) is unclear. Our aim is to ascertain the prognostic significance of these factors. Data from 348 patients (median age: 47.5 years old) with CC, diagnosed in two referral centers, were retrospectively collected. Advanced disease (FIGO2018 IB2-IV) was present in 68% of patients. A single HPV genotype was identified in 82.8% of patients. The most common HPVs were HPV16 (69%) and HPV18 (14%). HPV genera reflected this distribution. HPV16 tumors presented at an earlier stage. P16 was negative in 18 cases (5.2%), 83.3% of which were squamous cell carcinomas. These cases occurred in older patients who tended to have advanced disease. In the univariate analysis, HPV16 (HR: 0.58; p = 0.0198), α-9 genera (HR: 0.37; p = 0.0106) and p16 overexpression (HR: 0.54; p = 0.032) were associated with better survival. HPV16 (HR: 0.63; p = 0.0174) and α-9 genera (HR: 0.57; p = 0.0286) were associated with less relapse. In the multivariate analysis, only the International Federation of Gynecology and Obstetrics (FIGO) stage retained an independent prognostic value. HPV16, α-9 genera and p16 overexpression were associated with better survival, although not as independent prognostic factors. Patients with p16-negative HPV-associated CC were older, presented with advanced disease and had worse prognosis.

Targeted Therapeutic Approaches in Vulvar Squamous Cell Cancer (VSCC): Case Series and Review of the Literature

Therapeutic options in recurrent or metastasized vulvar squamous cell cancer (VSCC) not amenable to radiotherapy or radical surgery are limited. Evidence for the use of targeted therapies is sparse. All patients with VSCC treated at the Gynecological Cancer Center Hamburg-Eppendorf 2013–2019 were retrospectively evaluated for targeted therapeutic approaches. Furthermore, a MEDLINE, EMBASE, Web of Science, Scopus, and OVID database search was performed using the terms: “vulvar cancer” AND “targeted therapy,” “erlotinib,” “EGFR,” “bevacizumab,” “VEGF,” “pembrolizumab,” or “immunotherapy.” Twelve of 291 patients (4.1%) with VSCC received at least one targeted therapy at our institution. Previously, one or more platinum-based chemotherapy was applied to all patients [median 3.5 previous lines (range 2–5)]. In the erlotinib subgroup, two of five patients (40%) achieved stable disease (SD), while two patients (2/5, 40%) experienced partial response (PR). Treatment was given as monotherapy in second/third line for a median of 3.4 months (range 2–6 months). Bevacizumab (n = 9) was given as maintenance therapy after platinum-based first-line chemotherapy (9/9); best response was complete response (CR) (n = 2/9 22.2%). Median duration of treatment was 7 months (range 4–13 months) with two patients still under ongoing treatment. Best response in the pembrolizumab (n = 3) subset was SD (n = 1/3 33%). Treatment was given as monotherapy in second/third line for a median of 3.3 months (range 3–4 months). Nine of 12 patients (75%) experienced treatment-related adverse events (TRAEs), most commonly grade 1/2. Rapidly evolving antibody treatments have proven clinical benefit especially in HPV-driven tumor entities; however, clinical investigations in VSCC are still limited. These reported cases provide evidence for the clinical utility and feasibility while ensuring an acceptable safety profile.

Cancer attributable to human papillomavirus infection in China: Burden and trends

BACKGROUND

Human papillomavirus (HPV) is associated with a substantial percentage of cervical cancer, and a significant percentage of anal, penile, vaginal, vulvar, oral cavity, oropharyngeal, and laryngeal cancers. Understanding the burden and trends of HPV-attributable cancers is crucial to HPV prevention strategies. In the current study, the authors estimated the latest burden and trends of HPV-attributable cancers in China.

METHODS

Data from the following sources were used. The number of new cancer cases and cancer deaths in China were estimated based on the China Cancer Registry Annual Report. The population-attributable fraction was estimated using pooled high-risk HPV prevalence and biomarker-positive rates, which were calculated using random effects meta-analyses. Cancer burden estimates were stratified by anatomic site, sex, and age.

RESULTS

In 2015, a total of 110,650 new cancer cases and 36,714 cancer deaths attributable to HPV infection were estimated to have occurred in China, of which cervical cancer accounted for 85.6% and 78.1%, respectively. The age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) of HPV-attributable cancers were 5.63 and 1.81 per 100,000 person-years, respectively. The ASIR and ASMR both varied by anatomic site, with the highest rates noted for cervical cancer at 4.83 and 1.42 per 100,000 person-years, respectively. Between 2005 and 2015, the ASIR and ASMR demonstrated significant upward trends for all HPV-attributable cancers combined.

CONCLUSIONS

Between 2005 and 2015, cervical cancer accounted for the vast majority of HPV-attributable cancers and its incidence and mortality increased rapidly in China. The comprehensive prevention of cervical cancer remains the most important target in the prevention of HPV-attributable cancers.

Molecular pathways in vulvar squamous cell carcinoma: implications for target therapeutic strategies

BACKGROUND

Additional prognostic factors and personalized therapeutic alternatives for vulvar squamous cell carcinoma (VSCC), especially for advanced stages with poor prognosis, are urgently needed.

OBJECTIVES

To review and assess literature regarding underlying molecular mechanisms of VSCC target therapeutic and prognostic approaches.

METHODS

We performed a narrative literature review from the inception of the database up to January 2020 limited to English language, organizing knowledge in five main fields: extracellular and intracellular cell cycle deregulation, tumor immune microenvironment, tumor angiogenesis and hormones.

RESULTS

EGFR immunohistochemical overexpression/gene amplification, representing early events in VSCC carcinogenesis, have been correlated with a worse prognosis and led to inclusion of erlotinib in cancer guidelines. p16 expression and HPV positivity are linked to a better prognosis, while p53 overexpression is linked to a worse prognosis; thus, biomarkers could help tailoring conventional treatment and follow-up. The implications of PD-L1 positivity in reference to HPV status and prognosis are still not clear, even though pembrolizumab is part of available systemic therapies. The role of tumor angiogenesis emerges through data on microvessel density, immunohistochemical VEGF staining and evaluation of serum VEGF concentrations. Few data exist on hormonal receptor expression, even though hormonal therapy showed great manageability.

CONCLUSIONS

We suggest adding p16, p53 and HPV status to routine hystopathological examination of vulvar biopsies or surgical specimens. Predictive biomarkers for anti-EGFR and anti-PD-1/PD-L1 drugs are needed. Enough preclinical data supporting anti-angiogenic target therapies in clinical trials are existing. Hormonal receptor expression deserves further investigation.

Overexpression of p16INK4a Serves as Prognostic Marker in Squamous Cell Vulvar Cancer Patients Treated With Radiotherapy Irrespective of HPV-Status

Purpose: We aimed to evaluate the impact of HPV-driven carcinogenesis on outcome in vulvar squamous cell carcinoma patients (VSCC) treated with radiotherapy.

Methods and Materials: Analysis of clinical, pathological, and treatment data, HPV DNA-detection and -genotyping as well as p16^INK4a immunohistochemistry were performed in 75 VSCC patients. Kaplan–Meier-method was used to estimate locoregional control (LC), Progression-free survival (PFS), and Overall Survival (OS). Univariate survival time comparisons were performed using the log-rank-test. Chi-square/Fisher exact test was used to assess correlations between HPV DNA and p16^INK4a data, pathological, clinical, and treatment characteristics.

Results: 23/75 (30.67%) of all women had locoregional relapse, 7/75 (9.3%) systemic recurrence, and 35/75 (46.67%) died after a median follow-up of 26.4 months. 21.3% of the tumors were HPV DNA-positive, mostly (93.75%) for the high-risk (HR) HPV type 16. 25.3% showed p16^INK4a-overexpression. 17.3% showed concomitant HPV DNA- and p16^INK4a-positivity (cHPPVC). Patients with p16^INK4a-overexpression, irrespective of the HPV DNA status, showed significantly better PFS (5-year-PFS 69.3 vs. 39.2%, p = 0.045), LC (5-year-LC 86.7 vs. 56.7%, p = 0.033) and a strong trend for better OS (5-year-OS 75.6 vs. 43.9%, p = 0.077). Patients with cHPPVC showed a trend for better PFS (5-year-PFS 72.7 vs. 41.3%, p = 0.082) and OS (5-year-OS 81.1 vs. 45.7%, p = 0.084) but no significant benefit for LC.

Conclusions: Patients with cHPPVC, indicating an etiological relevance of HPV in the respective tumors, showed a better, albeit not significant, prognosis. The sole detection of p16^INK4a-overexpression is a prognostic factor for survival in vulvar cancer and indicates better prognosis after radiotherapy, independent of detection of HPV DNA. p16^INK4a should be used as surrogate marker for HPV-driven carcinogenesis in vulvar cancer with caution.

The prognostic value of p16 and p53 expression for survival after vulvar cancer: A systematic review and meta-analysis

The tumor suppressor proteins p16 and p53 have been suggested to have prognostic value in some human papillomavirus (HPV)-associated cancers, however, this has been less well established for vulvar cancer. The aim of this review and meta-analysis was to examine the prognostic value of p16 and p53 expression status on survival after vulvar squamous cell carcinoma (VSCC). We conducted a thorough systematic literature search of multiple databases to identify studies examining survival after histolocally verified VSCC that were tested for p16 and/or p53. A total of 18 eligible studies were included. Using a fixed-effects model we calculated study-specific and pooled hazard ratios (HRs) of 5-year overall survival (OS). In the analyses of OS, we included 475 VSCC cases tested for p16 expression of which 38% were p16 positive. The pooled HR_p16 was 0.40 (95% CI: 0.29-0.55). In addition, the majority of results from studies with adjusted analyses on the prognostic value of p16 indicated that p16 expression status could be an independent prognostic marker for OS in women diagnosed with VSCC, and the same pattern was seen for disease specific survival (DSS). We also included 310 VSCC cases tested for p53 expression of which 54% were p53 positive. The pooled HR_p53 was 1.81 (95% CI: 1.22-2.68) indicating that p53 positive VSCC have a significantly lower 5-year OS compared to p53 negative. The results in relation to p53 reported from adjusted analyses OS and on DSS and disease free survival were more equivocal. This meta-analysis and review suggests that p53 and especially p16 expression status are of prognostic importance in women diagnosed with VSCC. This may be clinically important in the future design of targeted therapy and when planning the optimal follow-up strategy. Future studies should include the combined use of biomarkers such as p16, p53 and HPV status.

Plasma endothelin-1-related peptides as the prognostic biomarkers for heart failure: A PRISMA-compliant meta-analysis

BACKGROUND

Most studies reported that high plasma endothelin-1 (ET-1), big ET-1, and C-terminal proET-1 (CT-proET-1) were correlated with poor prognosis of heart failure (HF). However, available evidence remains controversial. To help solve the debate, we collected all the available studies and performed a meta-analysis.

METHODS

We searched the databases covering Embase, PubMed, Ovid, and Web of Science on June 28, 2017. The hazard ratio (HR) or risk ratio (RR) and its 95% confidence intervals (CIs) were collected and calculated by use of a random-effect model. Heterogeneity was assessed by Cochran's Q test, and publication bias was assessed by funnel plots with Egger's and Begg's linear regression test.

RESULTS

Thirty-two studies with 18,497 patients were included in the analysis. Results showed that circulating ET-1, big ET-1, and CT-proET-1 were positively correlated with high risk of adverse outcomes, with pooled RRs (95% CIs) of 2.22 (1.82-2.71, P < .001), 2.47 (1.93-3.17, P < .001), and 2.27 (1.57-3.29, P < .001), respectively. In the subgroup of death as primary outcome, the pooled RRs (95% CIs) were 2.13 (1.68-2.70, P < .001), 2.55 (1.82-3.57, P < .001), and 2.02 (1.39-2.92, P < .001) for ET-1, big ET-1, and CT-proET-1, respectively. No significant publication bias was observed in this study.

CONCLUSION

Our meta-analysis provided evidence that increased plasma levels of ET-1, big ET-1, and CT-proET-1 were associated with poor prognosis or mortality for HF populations.

Viral Oncology: Molecular Biology and Pathogenesis

Oncoviruses are implicated in approximately 12% of all human cancers. A large number of the world's population harbors at least one of these oncoviruses, but only a small proportion of these individuals go on to develop cancer. The interplay between host and viral factors is a complex process that works together to create a microenvironment conducive to oncogenesis. In this review, the molecular biology and oncogenic pathways of established human oncoviruses will be discussed. Currently, there are seven recognized human oncoviruses, which include Epstein-Barr Virus (EBV), Human Papillomavirus (HPV), Hepatitis B and C viruses (HBV and HCV), Human T-cell lymphotropic virus-1 (HTLV-1), Human Herpesvirus-8 (HHV-8), and Merkel Cell Polyomavirus (MCPyV). Available and emerging therapies for these oncoviruses will be mentioned.

Local immune response depends on p16INK4a status of primary tumor in vulvar squamous cell carcinoma

BACKGROUND

The p16Ink4a is not a surrogate marker for high-risk human papilloma virus (HPV) genotypes but indicates better prognosis in vulvar squamous cell carcinoma patients. Our recent study confirmed substantial mismatch between p16Ink4a and high-risk HPV-status as well as revealed that p16Ink4a-overexpression itself is an independent prognostic factor for vulvar cancer.

AIM

To determine significance of the tumor infiltrating immune cells and p16Ink4a-status for better outcome of patients with vulvar cancer.

METHODS

Intraepithelial tumor infiltrating lymphocytes: CD8+, CD4+, FOXP3+, CD56+, tumor associated macrophages: CD68+, and GZB+ cells were calculated in 85 vulvar squamous cell carcinomas with previously defined p16Ink4a and high-risk HPV-status. Number of intraepithelial CD8+, CD4+, FOXP3+, CD56+, CD68+ and GZB+ cells were compared between tumors with different p16INK4a status and overlapping high-risk HPV-status separately. Survival analyses included the Kaplan-Meier method, log-rank test and Cox proportional hazards model.

RESULTS

p16Ink4a-negative tumors were more infiltrated by intraepithelial CD8+, CD4+ and GZB+ cells than p16Ink4a-positive tumors (p=0.032, p=0.016 and p=0.007 respectively). High-risk HPV-status did not correlate with the infiltration of immune cells. Median follow up was 89.20 months (range 1.7-189.5). High CD4+ and CD56+ indices were correlated with prognosis in p16Ink4a-positive cases (p=0.039 and p=0.013 respectively). Low CD68+ infiltrates were correlated with prognosis in p16Ink4a-negative cases (p=0.018).

CONCLUSION

p16Ink4a-status impacts local immune surveillance as represented by tumor infiltrating immune cells. Immunologic effects contributing to clinical outcome might depend on p16Ink4a-overexpression.

Role of Human Papillomavirus in Vulvar Cancer

Human papillomavirus (HPV) is involved in one of the at least 2 pathways leading to vulvar squamous cell carcinoma (VSCC). Inactivation of p53 and retinoblastoma by the viral products E6 and E7 is involved in malignant transformation. The percentage of HPV-positive VSCCs ranges from 18% to 75%, depending on the geographical area. HPV-associated tumors affect relatively young women and arise from high-grade intraepithelial lesions, identical to other HPV-associated premalignant lesions of the anogenital tract. HPV-independent tumors tend to affect older women and usually arise in a background of inflammatory skin disorders and a subtle variant of in situ lesion called differentiated vulvar intraepithelial neoplasia. HPV-positive tumors tend to be of basaloid or warty types, whereas HPV-independent tumors tend to be of keratinizing type, but there is frequent overlap between histologic types. There is no conclusive evidence yet on the best strategy in terms of determining HPV attribution. HPV DNA detection is generally considered the gold standard although there is some concern about misclassification when using this technique alone. p16 immunostaining has shown to be an excellent surrogate marker of HPV infection. Positive results for both techniques are considered the best evidence for HPV-association. The prognostic role of HPV in VSCC is still contradictory, but increasing evidence suggests that HPV-associated tumors are less aggressive. Currently, there are no differences in treatment between HPV-associated and HPV-independent VSCC, but novel immunological strategies based on anti-HPV antigens are being evaluated in clinical trials.

Do CDK4/6 inhibitors have potential as targeted therapeutics for squamous cell cancers?

Introduction Dysregulation of cell cycle progression has an established link to neoplasia and cancer progression. Components of the cyclin D-CDK4/6-INK4-Rb pathway are frequently altered in squamous cell carcinomas (SCCs) by diverse mechanisms, including viral oncogene-induced degradation, mutation, deletion, and amplification. Activation of the CDK4/6 pathway may predict response to CDK4/6 inhibitors and provide clinical biomarkers. Recently, the CDK4/6 inhibitor palbociclib showed clinical efficacy in combination with cetuximab in HNSCC patients. Areas covered This review focuses on the current research on the use of CDK4/6 inhibitors, comprising preclinical animal studies through phase II clinical trials across all SCCs. Expert opinion CDK4/6 inhibitors have a proven clinical benefit in breast cancer, but data on SCCs are sparse. Although frequent dysregulation of the cyclin D-CDK4/6-INK4-Rb pathway in SCCs suggests that targeting CDK4/6 may hold promise for improved clinical outcomes, single-agent activity has been modest in preclinical studies and absent in clinical studies. Combinations with immunotherapy or inhibitors of the PI3 K/mTOR or EGFR pathway may be effective. Given that SCCs caused by human papillomavirus have high levels of p16 and low levels of Rb, the CDK4/6 inhibitors are predicted to be ineffective in these cancers.